This invention relates to an internal combustion engine and particularly to a water cooling system for a two-cycle crankcase compression V-engine for use in outboard motors.
Outboard motor engines are generally water cooled with the cooling water pumped from and returned to the body of water through which the motor is operating. The pump provides a relatively high flow of water through the engine, with the pressure and flow rate directly related to the engine speed. The pump must provide sufficient cooling flow to keep the engine temperature relatively low under full load conditions. Generally prior art engines have used water pumps developing maximum pressures of approximately 20 psi at full throttle. One such prior art engine is disclosed in U.S. Pat. No. 4,082,068 to Hale, entitled V-Engine Cooling System Particularly for Outboard Motors and the Like.
Though such high pressure cooling systems are general satisfactory, it is recognized that higher pressure shortens pump life and increases the incidence of cooling system leakage.